Casing rotator

ABSTRACT

Disclosed herein is a casing rotator capable of distributing loads applied to bearings to protect the bearings even though verticality of a casing is not matched with verticality of an intermediate frame or an upper frame of a rotator. The casing rotator includes a lower frame unit, an intermediate frame unit, an upper frame unit, a clamping cylinder, and a post unit. The lower frame unit includes a lower frame, an outrigger, and a retainer portion. The intermediate frame unit includes an intermediate frame, a drive motor, a clamp body, and a drive bearing. The upper frame unit includes an upper frame, a wedge clamp, and an upper bearing. The clamping cylinder is configured to be stretchable. The post unit includes a guide post, a lower guide, a crowd cylinder, and an upper guide.

FIELD OF THE INVENTION

The present invention relates to a casing rotator, and more particularly, to a casing rotator capable of distributing loads applied to bearings to protect the bearings even though verticality of a casing is not matched with verticality of an intermediate frame or an upper frame of a rotator.

BACKGROUND OF THE INVENTION

A rotator is a device for foundation work, and is one of various devices for driving a casing into the ground. The rotator relatively easily secures verticality of the casing and is thus preferred in a construction field. However, since the rotator is expensive compared to a casing oscillator for performing the same work and has low torque, pressing and pulling force, or the like, the rotator is neglected in a construction field requiring a heavy load according to complex geological conditions.

However, the rotator is constantly used in a field in which geological conditions are relatively simple and work is able to be performed under a light load.

Korean Patent No. 10-0758113 discloses a method of constructing a large diameter drilled pile in underwater rock using such a casing rotator.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a casing rotator that substantially obviates one or more problems due to limitations and disadvantages of the related art.

Since a casing rotator digs using a casing, it is important to match verticality of the casing and the rotator. Accordingly, an object of the present invention is to provide a casing rotator capable of matching verticality of a casing using upper and lower guides.

In addition, since severe loads act on upper and lower bearings when verticality of a casing is not accurately matched with verticality of a rotator in the casing rotator, there is a problem in that the bearings are damaged. Accordingly, another object of the present invention is to provide a casing rotator capable of preventing severe loads from acting on upper and lower bearings even though axial lines of intermediate and upper frames do not coincide with each other.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In accordance with an aspect of the present invention, a casing rotator includes a lower frame unit, an intermediate frame unit, an upper frame unit, a clamping cylinder, and a post unit. The lower frame unit includes a lower frame having a through-hole into which a casing is inserted, an outrigger installed to the lower frame such that the lower frame is horizontally maintained and supported on a bottom, and a retainer portion installed to the lower frame so as to fix the casing inserted into the through-hole. The intermediate frame unit includes an intermediate frame located above the lower frame and having a through-hole into which the casing is inserted, a drive motor installed to the intermediate frame, a reduction gear portion for reducing a driving speed of the drive motor and for transferring the reduced speed, a clamp body having a through-hole formed therein such that the casing is inserted into the through-hole and coupled to the reduction gear portion so as to be rotatable by the reduction gear portion, and a drive bearing installed to the intermediate frame so as to support the clamp body. The upper frame unit includes an upper frame located above the intermediate frame and having a through-hole into which the casing is inserted, a wedge clamp inserted into the clamp body to grip the casing, and an upper bearing installed to the upper frame so as to support the wedge clamp. The clamping cylinder is configured to be stretchable such that the upper frame is vertically moved, one end of the clamping cylinder being fixed to the upper frame and the other end thereof being fixed to the intermediate frame. The post unit includes a guide post installed to the intermediate frame, a lower guide installed to the lower frame so as to be slidable along the guide post, a crowd cylinder configured to be stretchable such that the intermediate frame is vertically moved, one end of the crowd cylinder being fixed to the lower guide and the other end thereof being fixed to the guide post, and an upper guide fixed to the upper frame so as to guide the guide post when the guide post is vertically moved.

In the casing rotator, the guide post may include an upper guide post installed to an upper portion of the intermediate frame so as to be inserted into the upper guide, and a lower guide post installed to a lower portion of the intermediate frame.

In the casing rotator, the upper guide may have a penetrated support hole. In this case, the post unit may further include a guide housing for enclosing the upper guide and an elastic member installed to the guide housing so as to be inserted into the support hole and support the upper guide post.

In the casing rotator, the elastic member may be one of a leaf spring, a coil spring, and a rubber.

In the casing rotator, the elastic member may include a pressing body for pressing the upper guide post at the support hole, a hydraulic cylinder having a support spring therein and installed to the guide housing, and a piston, one end of which is coupled to the pressing body by a hinge, the piston being inserted into the hydraulic cylinder to be supported by the support spring such that the pressing body presses the upper guide post.

In the casing rotator, the lower guide and the crowd cylinder may be integrally formed. In this case, the outrigger may be installed to the lower guide.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating a casing rotator according to an embodiment of the present invention;

FIG. 2 is a front view of the embodiment shown in FIG. 1;

FIG. 3 is a top view of the embodiment shown in FIG. 1;

FIG. 4 is a side view of the embodiment shown in FIG. 1;

FIG. 5 is a perspective view illustrating a lower frame unit of the embodiment shown in FIG. 1;

FIG. 6 is a perspective view illustrating an intermediate frame unit of the embodiment shown in FIG. 1;

FIG. 7 is a perspective view illustrating an upper frame unit of the embodiment shown in FIG. 1;

FIG. 8 is a cross-sectional perspective view illustrating the embodiment shown in FIG. 1;

FIG. 9 is a partially enlarged view of FIG. 8;

FIG. 10 is a cross-sectional view of the embodiment shown in FIG. 1;

FIG. 11 is a partially enlarged view of FIG. 10;

FIG. 12 is a cross-sectional view when viewed from direction “A-A” in FIG. 2;

FIG. 13 is a cross-sectional view illustrating a post unit of the embodiment shown in FIG. 1;

FIG. 14 is another conceptual view of the post unit;

FIG. 15 is a cross-sectional view of FIG. 14.

FIG. 16 is a still another conceptual view of the post unit; and

FIG. 17 is a further conceptual view of the post unit.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. The drawings are not necessarily to scale and in some instances, proportions may have been exaggerated in order to clearly illustrate features of the embodiments.

Hereinafter, a casing rotator according to an embodiment of the present invention will be described with reference to FIGS. 1 to 13.

The casing rotator according to the embodiment of the present invention includes a lower frame unit 10, an intermediate frame unit 20, an upper frame unit 30, a clamping cylinder 40, and a post unit 50.

The lower frame unit 10 includes a lower frame 11, an outrigger 13, and a retainer portion 17. The lower frame 11 has a through-hole 11 a into which a casing may be inserted. The outrigger 13 is installed to the lower frame 11 such that the lower frame 11 may be horizontally maintained and supported on a bottom. The retainer portion 17 is installed to the lower frame 11 so as to fix the casing inserted into the through-hole 11 a. The retainer portion 17 includes a retainer 17 a and a retainer cylinder 17 b capable of enclosing the casting to fix the casing. When the retainer cylinder 17 b is contracted, the retainer 17 a encloses and fixes the casing.

The intermediate frame unit 20 includes an intermediate frame 21, a drive motor 23, a reduction gear portion 25, a clamp body 27, and a drive bearing 29. The intermediate frame 21 is located above the lower frame 11 and has a through-hole into which the casing may be inserted.

The drive motor 23 is installed to the intermediate frame 20. The reduction gear portion 25 reduces a driving speed of the drive motor 23 and transfers the reduced speed. To this end, the reduction gear portion 25 may include a reduction gear, a pinion, an idle, and the like. Since the drive motor 23 rotates at rapid speed, the reduction gear portion 25 reduces the speed and transfers the reduced speed. The clamp body 27 has a through-hole formed therein such that the casing may be inserted into the through-hole, and is coupled to the reduction gear portion 25 so as to be rotatable by the reduction gear portion 25. The clamp body 27 is coupled to the reduction gear portion 25 by gears, and rotates along with rotation of the reduction gear portion 25. In addition, the clamp body 27 has an inclined groove formed therein such that a wedge clamp 33 to be described later may be inserted into the inclined groove. The drive bearing 29 is installed to the intermediate frame 21 so as to support the clamp body 27. Thus, when the drive motor 23 rotates, the driving speed of the drive motor 23 is reduced by the reduction gear portion 25 and the drive motor 23 rotates the clamp body 27. Since the clamp body 27 is supported by the drive bearing 29, the clamp body 27 is rotatable relative to the intermediate frame 21.

The upper frame unit 30 includes an upper frame 31, a wedge frame 33, and an upper bearing 35. The upper frame 31 is located above the intermediate frame 21 and has a through-hole 31 a into which the casing may be inserted. The wedge clamp 33 is inserted into the clamp body 27 and serves to grip the casing. Since the groove of the clamp body 27 into which the wedge clamp 33 is inserted is inclined, the wedge clamp 33 is radially inwardly moved when the wedge clamp 33 is inserted into the groove. Thus, when the wedge clamp 33 is inserted into the groove, the casing inserted into the clamp body 27 may be gripped. The upper bearing 35 is installed to the upper frame 31 so as to support the wedge clamp 33. As a result, the wedge clamp 33 may rotate relative to the upper frame 31.

The clamping cylinder 40 is configured to be stretchable, and one end of the clamping cylinder 40 is fixed to the upper frame 31 and the other end thereof is fixed to the intermediate frame 21 such that the upper frame 31 is vertically moved. Thus, when the clamping cylinder 40 is stretched or contracted, the upper frame 31 is vertically moved relative to the intermediate frame 21. First, when the clamping cylinder 40 is contracted, the upper frame 31 moves downward. Consequently, the wedge clamp 33 is inserted into the clamp body 27 and grips the casing inserted into the clamp body 27. When the clamping cylinder 40 is stretched, the upper frame 31 moves upward. In this case, the wedge clamp 33 is ejected from the clamp body 27 and thus the casing is separated from the wedge clamp 33.

The post unit 50 includes a guide post 51, a lower guide 53, a crowd cylinder 55, and an upper guide 57.

The guide post 51 is installed to the intermediate frame 21. In this case, the guide post 51 is configured of an upper guide post 51 a and a lower guide post 51 b. The upper guide post 51 a is fixed to an upper portion of the intermediate frame 21 and the lower guide post 51 b is fixed to a lower portion of the intermediate frame 21.

The lower guide 35 is installed to the lower frame 11 so as to be inserted into the lower guide post 51 b and be slidable along the lower guide post 51 b.

One end of the crowd cylinder 55 is fixed to the lower guide 53 and the other end thereof is fixed to the guide post 51. The crowd cylinder 55 is stretched or contracted such that the intermediate frame 21 may be vertically moved. That is, when the crowd cylinder 55 is stretched, the intermediate frame 21 moves upward relative to the lower frame 11. In addition, when the crowd cylinder 55 is contracted, the intermediate frame 21 moves downward relative to the lower frame 11.

The upper guide is fixed to a lower portion of the upper frame 31 such that the upper guide 57 is inserted into the upper guide post 51 a and is slidable when the guide post 51 is vertically moved. Thus, when the crowd cylinder 55 is stretched or contracted, the guide post 51 is vertically moved. In this case, the guide post 51 is guided along the upper and lower guides 53 and 57.

Meanwhile, the outrigger 13 is installed to the lower frame 11, but may also be installed to the lower guide 57 as in the present embodiment.

Hereinafter, an operation of the casing rotator according to the embodiment will be described. First, in order to dig using the casing, the upper frame 31 moves downward by contraction of the clamping cylinder 40.

Next, the wedge clamp 33 is inserted into the clamp body 27 and then grips the casing. Subsequently, the clamp body 27 rotates by operation of the drive motor 23. Thus, the clamp body 27, the wedge clamp 33, and the casing rotate. The clamp body 27 is supported on the intermediate frame 21 by the drive bearing 29, and the wedge clamp 33 is supported on the upper frame 31 by the upper bearing 35. When the crowd cylinder 55 is contracted, the upper frame 31 and the intermediate frame 21 are moved downward and the casing digs. When the crowd cylinder 55 is contracted, the guide post 51 may be guided along the upper and lower guides 57 and 53 and move downward.

Meanwhile, in the casing rotator shown in FIGS. 1 to 13, when verticality of the casing is not matched with verticality of the rotator, severe loads are applied to the drive bearing 29 and the upper bearing 35, thereby causing the drive bearing 29 and the upper bearing 35 to be easily damaged.

In this case, in order to prevent the severe loads from being applied to the drive bearing 29 and the upper bearing 35, the post unit 50 may further include a guide housing 59 and an elastic member.

First, the elastic member is configured of a leaf spring 61 as shown in FIGS. 14 and 15. That is, the post unit 50 further includes the guide housing 59 and the leaf spring 61. In this case, the upper guide 57 has a plurality of support holes 57 a which penetrate an outer peripheral surface thereof and are formed in a circumferential direction. The guide housing 59 encloses the upper guide 57. The leaf spring 61 is supported by the guide housing 59 and is inserted into the support holes 57 a to support the upper guide post 51 a. In this case, when a central axis of the casing does not coincide with a central axis of the rotator, the guide posts 51 are deviated from each other. Therefore, the leaf spring 61 supports the guide posts. Consequently, the loads applied to the drive bearing 29 and the upper bearing 35 may be decreased.

Next, the elastic member includes a pressing body 63, a hydraulic cylinder 67, and a piston 71 as shown in FIG. 16. In this case, the upper guide 57 has a plurality of support holes 57 a which penetrate an outer peripheral surface thereof and are formed in a circumferential direction. The pressing body 63 presses the upper guide post 51 a at positions at which the support holes 57 a are formed. The hydraulic cylinder 67 and the piston 71 may allow the pressing body 63 to press the upper guide post 51 a. To this end, the hydraulic cylinder 67 is installed to the guide housing 65 and has a support spring 69 formed therein. One end of the piston 71 is inserted into the hydraulic cylinder 67 so as to be supported by the support spring 69 and the other end thereof is coupled to the pressing body 63. In the embodiment, the pressing body 63 presses the upper guide post 51 a by force of the supporting spring 69. Thus, when axes of the guide posts 51 are deviated from each other, the force is transferred to and absorbed by the support spring 69. Meanwhile, the hydraulic cylinder 67 serves to have an attenuation function when the piston 71 is moved by fluid received in the hydraulic cylinder 67. Consequently, it may be possible to prevent the piston 71 from rapidly moving. The elastic member may also be another buffer device such as a coil spring or a rubber, in addition to those described in the above embodiment.

Meanwhile, the lower guide 53 and the crowd cylinder 55 are separately formed and the crowd cylinder 55 is inserted into the lower guide 53 in the embodiment shown in FIGS. 1 to 13. However, the crowd cylinder and the lower guide may be integrally formed as shown in FIG. 17.

As is apparent from the above description, in accordance with an embodiment of the present invention, it may be possible to match verticality of a casing and a rotator since a guide post slides along upper and lower guides.

In addition, in accordance with the embodiment of the present invention, since an overload caused when axial lines of upper and intermediate frames do not coincide with each other is buffered by pressing of the guide post using a leaf spring or a pressing body, loads acting on upper and lower bearings may be reduced. Consequently, it may be possible to prevent the loads from severely acting on the upper and lower bearings.

Although the present invention has been described with respect to the illustrative embodiments, it will be apparent to those skilled in the art that various variations and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. 

1. A casing rotator comprising: a lower frame unit comprising a lower frame having a through-hole into which a casing is inserted, an outrigger installed to the lower frame such that the lower frame is horizontally maintained and supported on a bottom, and a retainer portion installed to the lower frame so as to fix the casing inserted into the through-hole; an intermediate frame unit comprising an intermediate frame located above the lower frame and having a through-hole into which the casing is inserted, a drive motor installed to the intermediate frame, a reduction gear portion for reducing a driving speed of the drive motor and for transferring the reduced speed, a clamp body having a through-hole formed therein such that the casing is inserted into the through-hole and coupled to the reduction gear portion so as to be rotatable by the reduction gear portion, and a drive bearing installed to the intermediate frame so as to support the clamp body; an upper frame unit comprising an upper frame located above the intermediate frame and having a through-hole into which the casing is inserted, a wedge clamp inserted into the clamp body to grip the casing, and an upper bearing installed to the upper frame so as to support the wedge clamp; a clamping cylinder configured to be stretchable such that the upper frame is vertically moved, one end of the clamping cylinder being fixed to the upper frame and the other end thereof being fixed to the intermediate frame; and a post unit comprising a guide post installed to the intermediate frame, a lower guide installed to the lower frame so as to be slidable along the guide post, a crowd cylinder configured to be stretchable such that the intermediate frame is vertically moved, one end of the crowd cylinder being fixed to the lower guide and the other end thereof being fixed to the guide post, and an upper guide fixed to the upper frame so as to guide the guide post when the guide post is vertically moved.
 2. The casing rotator according to claim 1, wherein the guide post comprises an upper guide post installed to an upper portion of the intermediate frame so as to be inserted into the upper guide, and a lower guide post installed to a lower portion of the intermediate frame.
 3. The casing rotator according to claim 2, wherein: the upper guide has a penetrated support hole; and the post unit further comprises a guide housing for enclosing the upper guide and an elastic member installed to the guide housing so as to be inserted into the support hole and support the upper guide post.
 4. The casing rotator according to claim 3, wherein the elastic member is one of a leaf spring, a coil spring, and a rubber.
 5. The casing rotator according to claim 3, wherein the elastic member comprises: a pressing body for pressing the upper guide post at the support hole; a hydraulic cylinder having a support spring therein and installed to the guide housing; and a piston, one end of which is coupled to the pressing body by a hinge, the piston being inserted into the hydraulic cylinder to be supported by the support spring such that the pressing body presses the upper guide post.
 6. The casing rotator according to claim 1, wherein: the lower guide and the crowd cylinder are integrally formed; and the outrigger is installed to the lower guide. 